This unit aims to provide students with a firm understanding of the physical chemistry that underpins pharmaceutical solutions and the impact of solution properties on a drug's biopharmaceutical characteristics. In particular, an understanding of the physicochemical properties of pharmaceutical solids (drugs and excipients), their transfer into solution form and properties of those solutions from a pharmacy and pharmaceutical science perspective will set the foundation for students to build upon in drug delivery units for solid and solution dose forms through second, third and fourth year of the course. The understanding of these principles will also assist students in their understanding in some areas of chemistry, physiology and biology.
This will involve:
- solutions of electrolytes and non-electrolytes, colligative properties and isotonicity
- solids and rheology
- solubility, diffusion, distribution, polymer solutions and solution formulations
- introduction to solution biopharmaceutics.
At the end of this unit students will be able to:
- Discuss the physicochemical principles that underpin the important processes of pharmaceutical solids dissolving to form a solution. In particular an understanding of dissolution, solubility and distribution are critical in many areas of pharmacy and pharmaceutical science;
- Describe the various forms of pharmaceutical solids, both drug forms and other components (excipients) and their role and impact when used to produce solution-based formulations;
- Discuss the basic physical chemistry of solutions once formed, including: the terms solution, supersaturation, solubility (ideal and non-ideal), solubility parameter, dissolution, distribution and partitioning, the influence of ionizable functional groups and structure on solution behaviour, the properties of polymers in solution and their rheological aspects and physical chemical concepts of solutions of non-electrolytes and electrolytes;
- Undertake calculations concerning the physico-chemical properties of drug solutions including changes in solubility with pH for ionisable compounds; calculate molar conductivities, ionic strength, partial pressures for ideal and non-ideal systems, and express solution concentrations in molarity, molality, mol fraction and equivalents;
- Suggest strategies typically used to improve drug solubility, and to outline the theories for prediction of drug solubility from solid state properties;
- Discuss the pharmaceutical applications of colligative properties of solutions and undertake calculations including molarity, molality, millimoles, miiliosmoles, gram percent concentrations and isotonic concentrations and isotonicity adjustment of solutions;
- Explain how drug transport across biological membranes is influenced by various physicochemical factors, in particular dissolution, ionization and distribution characteristics.
- Be proficient in basic laboratory techniques.
Final exam (2.5 hour): 60%; in-semester assessments 40%
Contact hours for on-campus students:
- Thirty six 1-hour lectures (27 face-to-face lectures + 9 hours active learning)
- Four 1-hour tutorials
- Four 3-hour practical laboratories
- Two 3-hour workshops
See also Unit timetable information